1. Field of Invention
The present invention generally relates to methods for recovery of hydrocarbons from hydrocarbon formations. More particularly, embodiments described herein relate to methods of enhanced hydrocarbons recovery and to compositions useful therein.
2. Description of Related Art
Hydrocarbons may be recovered from hydrocarbon containing formations by penetrating the formation with one or more wells. Hydrocarbons may flow to the surface through the wells. Conditions (e.g., permeability, hydrocarbon concentration, porosity, temperature, pressure) of the hydrocarbon containing formation may affect the economic viability of hydrocarbon production from the hydrocarbon containing formation. A hydrocarbon containing formation may have natural energy (e.g., gas, water) to aid in mobilizing hydrocarbons to the surface of the hydrocarbon containing formation. Natural energy may be in the form of water. Water may exert pressure to mobilize hydrocarbons to one or more production wells. Gas may be present in the hydrocarbon containing formation at sufficient pressures to mobilize hydrocarbons to one or more production wells. The natural energy source may become depleted over time. Supplemental recovery processes may be used to continue recovery of hydrocarbons from the hydrocarbon containing formation. Examples of supplemental processes include waterflooding, polymer flooding, alkali flooding, thermal processes, solution flooding or combinations thereof.
Compositions and methods for enhanced hydrocarbons recovery are described in U.S. Pat. No. 3,943,160 to Farmer et al., entitled “Heat-Stable Calcium-Compatible Waterflood Surfactant;” U.S. Pat. No. 3,946,812 to Gale et al., entitled “Use Of Materials As Waterflood Additives;” U.S. Pat. No. 4,077,471 to Shupe et al., entitled “Surfactant Oil Recovery Process Usable In High Temperature, High Salinity Formations;” U.S. Pat. No. 4,216,079 to Newcombe, entitled “Emulsion Breaking With Surfactant Recovery;” U.S. Pat. No. 5,318,709 to Wuest et al., entitled “Process for the Production of Surfactant Mixtures Based On Ether Sulfonated And Their Use;” U.S. Pat. No. 5,723,423 to Van Slyke, entitled “Solvent Soaps and Methods Employing Same;” U.S. Pat. No. 6,022,834 to Hsu et al., entitled “Alkaline Surfactant Polymer Flooding Composition and Process;” U.S. Pat. No. 6,269,881 to Chou et al., entitled “Oil Recovery Method For Waxy Crude Oil Using Alkylaryl Sulfonate Surfactants Derived From Alpha-Olefins and the Alpha-Olefin Compositions” and by Wellington, et al. in “Low Surfactant Concentration Enhanced Waterflooding,” Society of Petroleum Engineers, 1995; all of which are incorporated by reference herein.